EP0970919B1 - Apparatus for the disinfection of a water treatment unit - Google Patents

Description

The invention relates to a drinking water installation with a device for disinfecting a water treatment unit in the cold water part or hot water part.

The use of ion exchange materials, adsorbent and filter materials as well as filters (generally: water treatment units) in the drinking water sector is not unproblematic due to their potential for contamination. Different standards and regulations determine how to use these materials.

In the case of ion exchangers, for example, the standard DIN 19636 stipulates that disinfection of the resin bed and the system must be carried out at periodic intervals. Usually this disinfection is done by chlorination of the resin bed (for example by electrolytic generation of chlorine from the NaCl brine during the regeneration of the resin or by introducing hypochlorite, etc.). The use of chlorine for disinfection requires special care, since on the one hand a defined concentration exposure time for safe killing is necessary; On the other hand, chlorine damages the matrix of the resin and thus reduces the life of the ion exchange resin. Furthermore, it must be ensured that the resin bed is sufficiently rinsed after the chlorine disinfection, so as not to exceed the limits for chlorine in drinking water.

In the case of filter materials (sand filter, activated carbon, scale filter), but also conventional water filters, attempts are made to minimize the potential for contamination through prescribed backwash and replacement intervals. However, this does not offer safe protection against microbial contamination. It is therefore often attempted to additionally protect such plants by means of a downstream disinfection stage (UV, ozone, chlorination, anodic oxidation, etc.). The operation of such disinfection units is associated with great effort.

The thermal disinfection of water treatment units is known per se (eg. EP 0 372 293 A . EP 0 462 606 A ; US 4,610,790 ; EP 0621 239 A ).

The invention view a drinking water installation according to claim 1 of.

The heater is formed in or on the water treatment unit.

In principle, the water treatment unit can also be arranged in the hot water part of a drinking water installation. Due to the separate heating device, a higher temperature, for example above 60 ° C., preferably above 70 ° C., can also be achieved over a predetermined period of time, which permits reliable disinfection. So it is not necessary that the boiler has this high temperature.

• Das lonenaustauscher-, Adsorbentien- und Filtermaterial der Wasserbehandlungseinheit, aber auch das Material des Gehäuses bzw. die mit dem heißen Wasser in Berührung kommenden Teile der Anlage sind auf die für die Desinfektion erforderliche Temperatur ausgelegt (Ionenaustauscherharze vertragen üblicherweise Temperaturen bis 110°C, die Kalkfiltermaterialien und Aktivkohle vertragen Temperaturen wesentlich höher als 100°C). Gegebenenfalls vorhandene hitzeempfindliche Teile, wie z. B. Dichtungen können leicht gegen hitzefeste Teile ausgetauscht werden, sodaß auch eine Nachrüstung bestehender Anlagen möglich ist.
• Die Wasserbehandlungseinheit kann während der Hitzedesinfektion sauber vom Kaltwasser abgetrennt werden, wenn sie im Kaltwasserteil angeordnet ist. Über einen Bypass wird die Versorgung mit Wasser in der nachfolgenden Anlage sichergestellt.
• Die Heizeinrichtung für die Filter- oder Ionenaustauscheranlage kann verschieden ausgebildet sein, z. B. Heizmanschetten auf der Außenseite, Heizelement im entsprechenden Behältnis.
• Vorrichtungen zur Steuerung der Aufheizung, der Einhaltung der vorgesehenen Einwirkzeiten und zum Ausspülen des heißen Wassers sind für den Fachmann leicht zu realisieren. Dabei muß sichergestellt sein, daß die notwendige Sterilisationstemperatur überall im entsprechenden Ionenaustauscher- bzw. Filtermaterial erreicht wird.
• Vorrichtung zum Ausspülen des heißen Wassern in den Abfluß.

To carry out the heat disinfectant, the following components or conditions are favorable:

• The ion exchanger, adsorbent and filter material of the water treatment unit, but also the material of the housing or coming into contact with the hot water parts of the system are designed for the temperature required for disinfection (ion exchange resins usually tolerate temperatures up to 110 ° C, the Lime filter materials and activated carbon tolerate temperatures much higher than 100 ° C). Optionally existing heat-sensitive parts, such as. B. seals can be easily replaced with heat-resistant parts, so that a retrofitting of existing systems is possible.
• The water treatment unit can be separated cleanly from the cold water during the heat disinfection, if it is arranged in the cold water part. A bypass ensures the supply of water in the following system.
• The heating device for the filter or ion exchange system can be designed differently, for. B. heating sleeves on the outside, heating element in the corresponding container.
• Devices for controlling the heating, compliance with the intended exposure times and flushing of the hot water are easy to realize for the expert. It must be ensured that the necessary sterilization temperature is achieved everywhere in the corresponding Ionenaustauscher- or filter material.
• Device for flushing the hot water into the drain.

In-depth investigations of the Applicant with a weakly acid ion exchange resin have shown that, for example, cultures of pseudomonas aeruginosa are safely killed at 60 ° C and at exposure time of 1 hour. At a temperature of 70 ° C, 15 minutes are enough to kill these cultures safely.

The Fig.1 shows a first embodiment of a device according to the invention for disinfecting a water treatment unit in the cold water part of a drinking water installation,
the Fig. 2 shows an embodiment in which the water treatment unit, which is sterilized by heat, is arranged in the hot water part of a drinking water house installation.

The Fig. 1 shows the entrance 1 a drinking water installation in which cold water flows through the line 2. In this line 2, which then further into the house or in leads the apartment, a water treatment unit 3 is arranged with an ion exchanger 4. At the top of the container 5 of the water treatment unit 3 is a per se known four-way valve 6 is arranged. This has four ports 6a, 6b, 6c and 6d. In normal operation, water flows via the inlet 6a into the interior of the container 5, in which the ion exchanger 4 is arranged. The treated water then flows through the outlet 6b in the house or in the apartment. If the ion exchanger has to be treated, the valve 6 can switch to another position, in which the ports 6a and 6b are directly connected to each other in the sense of a bypass, ie the water does not flow over the container 5 in this case 6 c and the outlet 6 d open and connected to the container 5. It can therefore be filled brine 7 from a brine tank 8, for example via a pump, not shown, and the line 9 in the container 5 for the treatment of the ion exchanger 4. After the regeneration process, this brine can be guided via the line 10 into the drain 11.

As far as the system is state of the art and therefore needs no further description.

According to the invention, it is now provided to disinfect these arranged in the cold water part water treatment unit 3 by heat. There are several possibilities, in the illustrated embodiment, two of them are shown.

The first possibility is to apply heating sleeves 12 to the heat-conducting container 5. With these it is possible directly to disinfect the water contained in the container 5 and thus the ion exchanger 4. A temperature sensor 13 may be connected to a control unit, not shown, which ensures the action of a certain temperature over a certain time in periodically adjustable intervals. During the disinfection process, the water treatment unit is separated from the rest of the drinking water installation by the valve 6. The water can then flow in the bypass from the point 6a to 6b.

An alternative option for thermal disinfection is for simplicity also in Fig. 1 shown. It consists in heating the brine 7 by means of a heating element 14 and in the regeneration of the ion exchanger 4, in the the water treatment unit is in any case separated from the drinking water installation, at the same time carry out the thermal disinfection. It is simply heated the brine 7 and filled the hot brine in the container 5. This has the additional advantage that the regeneration process itself runs much faster and the brine is a particularly efficient disinfectant. For disinfection, the temperature of the brine may be above 70 ° C, preferably above 80 ° C, amount. After regeneration or disinfection, the hot brine can be rinsed into the drain with rinse water. The temperature monitoring takes place via the sensor 15.

In general, it will not be necessary to provide the heating jackets 12 and the heating element simultaneously in one device. Rather, it will be enough to use either the heating jackets or the heating element 14.

Although with the invention preferably arranged in the cold water part of a drinking water installation water treatment units can be thermally disinfected, the invention can in principle be applied to a water treatment unit arranged in the hot water part, as in Fig. 2 is shown.

At the in Fig. 2 illustrated embodiment, a first water treatment unit 17 is provided in the cold water part 16, which operates, for example, by electrostatic means and is connected to a control unit 18. This water treatment unit 17 is not thermally disinfected in the illustrated embodiment.

In the hot water part of a water heater 19 (boiler) is provided. In the circulation line 20, a second water treatment unit 21 is provided which has an ion exchanger 22. The circulation pump is designated by 23. In the vessel 5 of the water treatment unit 21 designed as a heating rod heater 24 is provided, which is separate from the water heater 19 and thus allows efficient and targeted heating of the water in the water treatment unit 21 and this or especially the therein arranged catalytically acting ion exchanger 22 thermally disinfect.

The invention can be applied not only to water treatment units with ion exchangers, but also to filters or adsorbents.

Claims (4)

1. A domestic drinking water installation comprising a cold water portion or a hot water portion with a hot water producing device (19) arranged in the hot water portion, wherein provided in the cold water portion or in the hot water portion is a water treatment unit (3, 21) which includes a filter and/or an adsorbent and/or an in particular catalytically acting ion exchanger (4, 22), characterised by a device for disinfecting the water treatment unit (3, 21), having a heating device (12, 14, 24) which in the case of the hot water portion is separate from the hot water producing device (19), wherein the heating device (12, 14, 24) is so arranged or is so connected to the water treatment unit (3, 21) that the water in the water treatment unit (3, 21) is heatable at times to a temperature of over 60°C, preferably over 70°C, wherein there is provided a valve arrangement (6) for separating the water treatment unit (21) at times from the rest of the domestic drinking water installation, and wherein there is further provided a bypass in relation to the water treatment unit (3, 21) to maintain the water supply in the case of a water treatment unit (3, 21) which is separated from the domestic drinking water installation, wherein the heating device (12, 14) is arranged in or at the water treatment unit (3), or the heating device (14) is arranged in a vessel (8) which is separated from the water treatment unit (3) and which is connected to the water treatment unit (3) by way of a conduit (9) and the separate vessel (8) is the brine vessel for treatment of an ion exchanger (4) in the water treatment unit (3).
2. A domestic drinking water installation according to claim 1 characterised by an apparatus for flushing out the heated water present in the water treatment unit (3, 21) into a drain (11).
3. A domestic drinking water installation according to one of claims 1 and 2 characterised in that the heating device which is preferably in the form of a heating bar (24) is arranged in a water-filled container (5) of the water treatment unit (3) itself.
4. A domestic drinking water installation according to one of claims 1 and 2 characterised in that the heating device which is preferably in the form of a heating jacket (12) is arranged externally on a heat-conducting, water-filled container (5) of the water treatment unit (3).

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